m2 and relay problem.

Guys i need some help again.

Last days i did some work in the car adding some things ( line in for vw mfd, and microphone - thanks Camo) . The way i wired them seems to be wrong. So until now i had my two screens powering from m2 psu. This was something i didn't like cause i was putting load to the m2 and probably raising the whole case temp. So after chinatobby told me that his 8" screen can stand unregulated power i thought that i had to send to the microphone and lcd power not through the psu.

So i did. I wired in parallel a 12v bosch 5 contacts relay and connected on it the lcd and the microphone. So again i got a kind of a failure.

What is happening now is that when i am swithcing of the display the m2 for some reason doesnt send signal for shut down to the mobo instead of that it does a hard reset to the computer.

If i disconnect the contact that sends the signal ( on - off ) to the relay everything is working normal again . I mean switch off and after 5 sec the mobo takes a shut down command.

So what have i done wrong here ? Am i trying something that cant be done ?

So to be clear you want the screen and mic to turn on and off with computer? controlled by the m2? SNO

No i can turn it on and off using the button . the problem is that it is ( the carpc) doing a hard reset when i am switching off the button. normally ( without relay ) it sends a "shutdown" command . that's what i want a shutdown command with relay on parralel.

Without a diode you are getting a spike on the feed line and your m2 is cutting the power.

Otherwise insure you are truly connected as your diagram shows and test your relay to make sure it is working properly. Guessing you are probably wired properly since the monitors come on but double check just to make sure.

You should also test your circuit with no monitors hooked up and try with just one monitor hooked up and then the other. Make sure one of your monitors isn't causing the issue.

Without a diode you are getting a spike on the feed line and your m2 is cutting the power.

very helpful . so what i got was that i have to put a diode in parallel ( my simple knowledge would put it in series ) with the +12v which going on m2 and to the 30th pin of the relay . Is this correct. If so what kind of diode ?

Originally Posted by redheadedrod

Otherwise insure you are truly connected as your diagram shows and test your relay to make sure it is working properly. Guessing you are probably wired properly since the monitors come on but double check just to make sure.

You should also test your circuit with no monitors hooked up and try with just one monitor hooked up and then the other. Make sure one of your monitors isn't causing the issue.

Now i am . yesterday morning the 85 and 86 was wrong. I ll test the relay .
Everything works fine if i unplug the relay . both of the screens and the m2.

I haven't had this issue but I believe the answer is yes.. The Diode goes on the coil side so there is VERY little amperage involved so a very simple diode will work. I am not sure how the diode is supposed to be hooked up but when you look at a diode the polarity is such that the line is on the negative end of the Diode.

I am not sure which way the diode goes but if you do a Google search for Diode on Relay you should get many examples.
Otherwise something sounds Weird in your circuit. It SHOULD work.

You could also make sure you run wires directly to your power source for the relay and ground directly to the mic and monitor(s). You are less likely to have interference from your devices and relay if the wiring is separated.

In my system I have an 8 gauge power source going to an auxiliary fuse box. From this fuse box I run power for my ignition relay, my retained accessory power relay, and I run a power lead directly to my m3 power supply. I engage the ignition relay from the ignition switch and the RAP relay directly from the BCM. (The BCM lead normally powers a sun roof relay so I know it is intended for a relay.) I will be adding a third relay to power amplifiers and other equipment from the amp turn on lead for any add on amplifiers and any other devices that need to be powered when the computer is on.

I power my monitor from the RAP lead to turn it off when my truck is off otherwise it should be the same.

I will also be putting a simple switch on the lead to the relays for the ignition and RAP to turn them on in case I want to work on the computer without having to turn the truck on. I am not using any power from the factory wiring. Just using it for switching my relays on and off. The 8 gauge wire running directly to the battery powers all of my computer equipment. (Will be hooked to a secondary battery once I get one. )

I spelled out my system for you to see how I am doing it to offer ideas.

Yes I thought you had used the relay wrong. The pins 86/85 are for power to the coil the diode should go between the 86/85 pin with the marked end of the diode to the 86 pin this is just an example for the diode placement not your circuit. pin 30 should be for what you want turned on or off and pin 87 is "what you want to turn off or on with relay, pin 87 is normally open and pin 87a is normally closed p.s. www.the12volt.com is a great source of information on relay circuits Good luck SNO

ok guys . problem solved . installed a diode between 85 and 86 pins ( cables to tell it right ) and now everything working as they should be . i mean i am swithicng off the button then the lcd switch off and after 5 sec ( m2 timer jumper selection |) the computer takes a shutdown command.

thanks both of you for the help you provided.

sno the plan you gave is the oposite of what i am doing . i mean on 30 i am sending fused input and on 87 or 87a i am getting output.